Gastric inhibitory polypeptide (GIP) is a gastrointestinal hormone having gastric acid secretion inhibitory action or gastric motility inhibitory action, and it is known that secretion thereof is enhanced by lipids and the like in the diet during food intake (Non-Patent Documents 1 to 3). Therefore, a substance inhibiting the secretion of GIP is believed to be useful in the facilitation of digestion or in the improvement of a heavy feeling in the stomach. Previous studies have reported that
3-bromo-5-methyl-2-phenylpyrazolo[1,5-a]pyrimidin-7-ol (BMPP) inhibited functions of GIP, and that guar gum and the like inhibited postprandial secretion of GIP (Patent Document 1 and Non-Patent Documents 4 to 9).
However, the former substance BMPP has not been verified to have an inhibitory effect on functions of GIP in vivo, while the latter substances guar gum and the like have a problem that their GIP secretion inhibitory effect during lipid ingestion has not been examined. Further, the effect of the above substances on improving a heavy feeling in the stomach or the like is not necessarily satisfactory.
Under such circumstances, the Applicant of the present invention found that when the sodium salt of alginic acid, which is one of the high molecular weight acidic polysaccharides present in brown algae, was fed to a mouse, a postprandial GIP secretion was inhibited, and that the sodium salt of alginic acid can thus serve as a postprandial GIP secretion inhibitor. The Applicant filed a patent application based on the finding (Patent Document 2).
On the other hand, potassium alginate is widely used as a thickening agent for food products or as a gelling agent in the preparations for dental impression, and is also reported to have a hypotensive action which is based on the mechanism of sodium excretion in the body (Non-Patent Document 10).
However, it has not been known that potassium alginate has a very excellent GIP secretion inhibitory action.
[Patent Document 1] WO 01/87341
[Patent Document 2] JP2006-342085
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